->count()

Описание

It performs a select count() request on the tables key column and returns the number of resulting rows. The default condition applied to the count() is a combination of the object variables and whereAdd settings. If the constant DB_DATAOBJECT_WHEREADD_ONLY is passed in as the first parameter then only the whereAdd settings will be used.

Параметр

• string $countWhat - by default count will count on the primary key, if you need to count something else, if you just say DISTINCT, it will count the primiary key prefixed with distinct, or put your own value in (dont forget to escape it if necessary)

• boolean $useWhereAddOnly - use only the whereAdd conditions (by default, count will only use both the object settings and the whereAdd conditions)

Возвращаемое значение

int|false - number of results or false on an error

Заметка

Эта функция не должна вызываться статически.

Пример

<?php 

/* using property values */
$person = new DataObjects_Person;
$person->name  = "test"
$total = $person->count();
echo "There are {$total} people with a name like test";

/* using countWhat */
$person = new DataObjects_Person;
$total = $person->count('DISTINCT name');
echo "There are {$total} names in the database";

/* using countWhat value = DISTINCT */
$person = new DataObjects_Person;
$total = $person->count('DISTINCT');
echo "There are {$total} names in the database";

/* using whereOnly */
$person = new DataObjects_Person;
$person->name = "test";
$person->whereAdd("name like '%test%");
$total = $person->count(DB_DATAOBJECT_WHEREADD_ONLY);
echo "There are {$total} names in the database";

?>

SELECT count(person.id) AS DATAOBJECT_NUM 
    FROM person 
    WHERE person.name = 'test';

SELECT count(DISTINCT name) AS DATAOBJECT_NUM 
    FROM person;

SELECT count(DISTINCT person.id) AS DATAOBJECT_NUM 
    FROM person;

SELECT count(person.id) AS DATAOBJECT_NUM 
    FROM person 
    WHERE name like '%test%';